Method and Process to Produce a Medical Device

ABSTRACT

The inventive method for manufacturing a medical device having a shuttle mold system mounted in a vertical injection molding machine, the shuttle mold system having a top section and two bottom sections, with the two bottom sections mounted 180 degrees from each other on a rotating table and the top section mounted in a fixed position above the rotating table, and where after molding, the table rotates 180 degrees for removal of parts and inserting fixtures for the next device manufacture cycle.

CROSS-REFERENCE TO RELATED APPLICATIONS

This Application is a divisional of application Ser. No. 16/381,704filed Apr. 11, 2019 which claims the benefit of and priority to U.S.Provisional Application No. 62/656,701, filed Apr. 12, 2018, the entirecontents of which are herein incorporated by reference.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH

Not Applicable

FIELD OF THE INVENTION

The invention relates to a method and apparatus for making a medicaldevice, and more specifically a method of molding a hub directly to amicro plastic tube and molding a tip containing a micro orifice at aspecified angle directly to the micro plastic tube.

BACKGROUND OF THE INVENTION

Manufacturing a medical device using a micro plastic tube can be verydifficult. It can be difficult to mold a hub onto the plastic tube,especially so that the plastic tube is adequately retained in the hubafter molding without causing blow out, pull out or fall out. It canalso be difficult to mold a tip onto the plastic tube without causingany obstructions or partial blockages for liquid flow out of the orificeend of the plastic tube.

BRIEF SUMMARY OF THE INVENTION

This medical device serves as a delivery system for administering liquidmedications in humans and animals. Applicant has developed methods andprocesses to enhance the manufacturing and performance of the device.These developments relate to the manufacturing methods and processesrequired to achieve critical requirements for the functionality of thedevice. Specifically they relate to the fluid flow characteristics andmechanical aspects of the device to ensure reliable performance.

The inventive method for making a medical device includes providing amicro plastic tube; molding a hub onto the tube; trimming the tube to apredetermined length; molding a tip onto the tube, and creating a tipthat contains a micro orifice at a predetermined angle.

The predetermined angle can be 45 degrees. The micro orifice at the tipcan be between 0.008 to 0.012 inches in diameter. The plastic tube has athin wall of approximately 0.003 inches thick. The plastic tube can bemade of PEBAX and the hub can be made of polycarbonate.

The micro orifice is created using a conically shaped orifice pin. Theapparatus used to make the medical device is created using a shuttlemold system and a vertical injection molding machine. The shuttle moldsystem has one top section and two bottom sections. The shuttle moldsystem is mounted in a vertical injection molding machine with the twobottom sections mounted 180 degrees from each other on a rotating tableand the top section mounted in a fixed position above the rotatingtable. After molding, the table rotates 180 degrees for removal of partsand inserting fixtures for the next device manufacture cycle.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view of a micro plastic tube molded to a plastic housing.

FIG. 2 is a view of the tooling fixture with the tube installed on atooling fixture pin to be placed in a mold for over molding the hub ontothe tube.

FIG. 3 is a view showing the tooling fixture after over molding the hubinto the micro plastic tube.

FIG. 4 is a view showing the interface between the tube and the hub.

FIG. 5 is a view showing the tip over molded onto the plastic tube.

FIG. 6 is a view showing the tube trimmed to a specified length.

FIGS. 7A and 7B is a view showing the trimmed tube placed on anotherfixture and positioned in the mold.

FIG. 8 is a view showing the special pin which produced the microorifice in the over molded tip.

FIGS. 9A and 9B show the pin and an enlarged view of the end of the pin.

FIGS. 10A and 10B show the tooling for making the tip and an enlargedview of the pin positioned to make the tip.

FIG. 11 shows the over molded tip on the end of micro tube.

FIG. 12 shows the tip and the orifice in the tip which is placed at a 45degree angle.

FIGS. 13A and 13B show the slide holding the pin in the forward positionand the back positions.

FIG. 14 shows the shuttle mold system in an open position.

FIG. 15 shows the shuttle mold system in a closed position.

FIG. 16 shows the rotating table portion of the shuttle mold system.

FIG. 17 shows one of the two bottom sections mounted 180 degrees fromeach other on the rotating table.

FIG. 18 shows the other of the two bottom sections.

DETAILED DESCRIPTION OF THE INVENTION

While this invention may be embodied in many forms, there are describedin detail herein specific embodiments of the invention. This descriptionis an exemplification of the principles of the invention and is notintended to limit the invention to the particular embodimentsillustrated.

For the purposes of this disclosure, like reference numerals in thefigures shall refer to like features unless otherwise indicated.

The method for manufacturing this product consists of a shuttle moldsystem and vertical injection molding machine. The shuttle mold systemhas one top section and two bottom sections. The shuttle mold system ismounted in a vertical injection molding machine. The two bottom sectionsare mounted 180 degrees from each other on a rotating table and the topsection is mounted in a fixed position above the rotating table. The twobottom sections move as the table rotates 180 degrees and align with theone top section during molding. After molding the table rotates 180degrees for removal of parts and inserting of fixtures for the nextcycle. The bottom sections are accessible to the operator at the frontof the machine during each index for inserting and removing fixtures andcomponents. The process requires a highly skilled operator to performall necessary functions such as: preparing the fixtures, loadingfixtures, ensuring sub-assemblies are positioned properly, and removingparts and fixtures. This is a continuous process that requires operatorinteraction for the molding operations.

The method for manufacturing this product consists of two stages. Instage 1 the micro plastic tube 12 is molded to a plastic housing 14 asshown in (FIG. 1). First, the micro plastic tube 12 is placed on atooling fixture 16 consisting of a pin (not shown because under theplastic tube) that matches the inside diameter of the tube (FIG. 2). Thefixture 16 containing the tube 12 is placed in a mold and the hub 14 isover molded on the tube 12 (FIG. 3). In effect the tube 12 and fixture16 acts as an insert for over molding the hub 14.

This process is critical because it determines the retention of the tube12 to the hub 14 while maintaining the integrity of the inside diameterof the micro plastic tube 12 during molding (FIG. 4) which is criticalfor the proper performance of the product in the end use application.The flow through the tube 12 cannot be obstructed by excess material,flash, debris, etc. The specific configuration of the tooling fixtureand set up in the mold minimizes this occurrence.

FIG. 2 shows the tooling fixture 16 with tube 12 installed on toolingfixture pin (inside tube 12) to be placed in mold for over molding thehub 14.

FIG. 3 shows the tooling fixture 16 after over molding the hub 14 on themicro tube 12. The tube to hub interface 18 (seen best in FIG. 4) iscritical to obtain adequate tube 12 retention to the hub 14 withoutjeopardizing the integrity of the opening in the tube during overmolding. This is accomplished by ensuring that the exact location of theplastic tube is maintained on the fixture 16 during the process of overmolding the hub 14, and ensuring the fixture set up in the mold isprecisely maintained.

The second stage is over molding a tip 20 containing a micro orifice 22(0.008″-0.012″) at a specified angle on the micro plastic tube 12. Thesub-assembly from the first step is placed on a tooling fixture 24 (seeFIG. 7A) consisting of a pin 26 that matches the inside diameter of thetube 12. The fixture 24 is placed in a mold and the tip 20 is overmolded on the micro plastic tube 12 (FIG. 5). The tube 12 and hub 14with tooling fixture 24 act as an insert for over molding of the tip 20.This method is critical because it creates the molded tip 20 on the endof the plastic tube that contains a micro orifice 22 at a 45 degreeangle (or any desired angle). In addition the tip 20 must be adequatelyattached to the tube 12 to maintain retention without causing anyobstructions or partial blockages for liquid flow. The configuration ofthe tooling and molding process prevent this from occurring.

FIG. 6 shows the tube after being trimmed to a predetermined length. Thehub 14 and micro tube 12 assembly requires a specific length of tube forsuccessful over molding of the tip on the end of the micro tube. Thetube length is determined by precisely placing the assembly on acalibrated fixture and trimming the tube to a specific length prior toover molding the tip. The tube is trimmed to fit the pin or mandrel usedin the molding process and can therefore be any desired length.

FIGS. 7A and 7B shows the fixture, shown generally at 24, which is usedonce the hub and tube assembly is trimmed to proper length and is readyfor over molding the tip 20 on the micro tube 12. The assembly is placedon fixture 24 and positioned in the mold.

FIG. 8 shows the special pin 26 used to produce the micro orifice 22 inthe tip 20 during the molding. FIG. 8 shows the fixture configured toproduce a micro orifice 22 in the tip 20 during over molding.

FIGS. 9A and 9B show an example micro orifice of 0.010 inches overmolded into tip 20, with the orifice 22 placed at a 45 degree angle. Theconically shaped tip of pin 26 has a 0.010 inch diameter pin 30 whichcreates the micro orifice. FIGS. 10A and 10B also show this step infurther detail. FIG. 11 shows the tip 20 produced by pin 26. FIG. 12shows the tip 20 is over molded to tube 12 in such a way that retentionis maintained without obstructions in the micro orifice 22.

FIGS. 13A and 13B shows the tooling configuration for over molding tip20 on micro tube 12. FIG. 13B shows the slide 32 in the back positionand FIG. 13A shows the slide 32 in the forward position. The slide 32with special pin 26 “shuts off” against the pin that is part of the huband tube assembly fixture.

FIG. 14 shows the shuttle mold system in an open position.

FIG. 15 shows the shuttle mold system in a closed position.

FIG. 16 shows the rotating table portion of the shuttle mold system.

FIG. 17 shows one of the two bottom sections mounted 180 degrees fromeach other on the rotating table.

FIG. 18 shows the other of the two bottom sections.

What is claimed is:
 1. An apparatus for manufacturing a medical devicecomprising: a shuttle mold system mounted in a vertical injectionmolding machine, the shuttle mold system having a top section and twobottom sections, with the two bottom sections mounted 180 degrees fromeach other on a rotating table and the top section mounted in a fixedposition above the rotating table, wherein after molding, the tablerotates 180 degrees for removal of parts and inserting fixtures for thenext device manufacture cycle.
 2. The apparatus of claim 1 wherein themedical device has a micro plastic tube with a hub molded onto the tubeand a tip on the end of the tube with a micro orifice being constructedand arranged in the tip at a predetermined angle relative to the tube.3. The apparatus of claim 2 wherein the predetermined angle is 45degrees.